640
FXUS63 KMPX 240019
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
619 PM CST Sat Nov 23 2024

.KEY MESSAGES...

- Two cold fronts over the next week will send highs from around
  40 this weekend, down into the 20s and low 30s mid week, then
  teens and 20s over Thanksgiving weekend.

- Confidence continues to increase in a mix of rain and snow
  Sunday night into Monday morning with minimal accumulations.

&&

.UPDATE...
Issued at 558 PM CST Sat Nov 23 2024

Quick update that the confidence continues to increase in
rain/snow chances Sunday evening/overnight. Precipitation will
develop right overhead late Sunday, which makes timing a bit
tricky since we won`t be tracking an incoming area of rain/snow,
but did continue the previous shift`s trends of increasing
pops. Forecast soundings show saturation as sites along a line
from Alexandria through St Cloud to Rice Lake and Ladysmith mainly
after 6pm, with most areas along and north of a line from
expected to see rain/snow after 9pm. The ensemble guidance has
80 to 90% of its members showing at least some precip for areas
north of this line. Surface temperatures should be warm enough
for rain at the onset, but the thermal profile cools which will
allow for a transition to snow. The sub- freezing temperatures
linger into Monday morning, so expect some slick spots on road
for areas that do see snow. Snow amounts are still expected to
be light, generally less than an inch.

&&

.DISCUSSION...
Issued at 238 PM CST Sat Nov 23 2024

Although not low stratus, it`s still cloudy as mid & upper level
clouds from the remnants of what was one of the strong storms to
impact the Pac NW last week moves across the northern Plains. We`ll
continue to see plenty of cloud cover the rest of the weekend,
though forecast soundings don`t show the depth of atmospheric
saturation being enough to support precip until Sunday evening.
Tonight, that cloud cover will remain of the mid/upper level
variety, but as southeast winds become established on Sunday and
weak WAA picks up, we`ll likely see low stratus develop. That
stratus is expected to develop in western MN first, closer to an
inverted trough/cold front that will be moving across the Dakotas
during the day, with stratus spreading east Sunday afternoon as that
trough approaches western MN.

As for Sunday night, we`re seeing models come into better agreement
on the timing/placement of forcing for precipitation and are showing
that it is increasingly likely we`ll see a rain and snow mix across
the MPX area Sunday evening into early Monday morning. The primary
upper air feature will be an h5 low going across southern Canada
Sunday night and northeast MN on Monday. However, within the
westerly flow to the south of this low, a shortwave is forecast to
eject out of WY/CO on Sunday, going across MN/IA Sunday night and WI
on Monday. The combination of PVA ahead of the shortwave, WAA ahead
of the inverted trough, and weak low level convergence along that
boundary will all work together to create light precipitation north
of the upper MN Valley Sunday night. The highest precipitation
totals still look to fall north of I-94, but most EPS members show
at least light precip as far south as Mankato. Because of that, we
expanded mentionable PoPs quite a bit to the southwest Sunday night,
while also introducing some likely PoPs north of I-94 in WI. For P-
type, forecast sounding and CAM output show this being a rain or
snow scenario based on surface temperatures. Given the overnight
timing, much of it will be snow. QPF looks light, so snow amounts
look light as well, though the HREF LPMM QPF shows potential for
0.10" of QPF down to the US-8 corridor in northwest WI, which if
that were to happen would likely translate to an inch or two of snow.

For Thanksgiving week, the big story continues to be the first taste
of arctic air we`ll see this season coming over the holiday weekend.
Our first cool down will come with the passage of that inverted
trough/front Sunday night/Monday morning. This will knock highs back
into the 20s/low 30s for Monday through Thursday. It looks dry for
the first half of the week, with a low looking to get spun up in the
southern stream Tuesday night that will head across the mid-MS
Valley on Wednesday and Ohio Valley on Thanksgiving, to far south
for us to get anything meaningful out of it at this point, though
there is an increasing signal for impactful snowfall accumulations
Wed/Thu from the Quad Cities over to Cleveland, something to keep an
eye on if you have some long distance travel plans. For us,
Thanksgiving Day proper is when the arctic front arrives. It will be
moisture starved, though there could very well be enough moisture
present with the forcing to squeeze out some light snow. The biggest
impact of this boundary will be the well below normal temperatures
we`ll have to end the month. If you`re one that wants to relive the
glory days of the 90s by camping out in front of one of your
favorite stores Thursday night to get an early jump on Black Friday
deals, you better bundle up, as we`ll likely have sub-zero wind
chills to start Black Friday. For the rest of the weekend, if
anything, the NBM is running a little warm as the bias corrected
data set it is trained on was trained on what up until this point
has been the warmest fall on record. This means that just getting
out of the teens for highs may be difficult to do Friday through
Sunday. As for your travel plans for the end of the holiday weekend,
it looks cold and dry and so long as you`re not trying to drive
downwind of a Great Lake, you shouldn`t run into any weather issues
on the roads.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 558 PM CST Sat Nov 23 2024

VFR conditions across the region with mid level clouds. Winds
are starting to become more easterly, and that trend will
continue. Forecast soundings show some low level dry air, so did
push back the onset of MVFR clouds from tonight into Sunday
morning. Expect an area of rain to develop and change over to
snow at KAXN, KSTC, and KRNH after 00Z, but this is beyond the
TAF time.

KMSP...
VFR conditions overnight into Sunday morning, with MVFR clouds
developing Sunday afternoon. Late Sunday evening some light rain
is expected to develop, and this should change over to snow as
surface temperatures fall overnight. Any snow accumulation
should only be a dusting or less.

/OUTLOOK FOR KMSP/
MON...VFR/MVFR, chc -RASN early. Wind NW 10-15G25 kts.
TUE...VFR. Wind NW 5-10 kts.
WED...VFR. Wind E 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

UPDATE...JRB
DISCUSSION...MPG
AVIATION...JRB